Attackers believed to be working out of Iran have manipulated the DNS records of dozens of organizations around the globe to intercept and record their network traffic in what appears to be a large and growing espionage campaign.
Among those affected are commercial entities, government organizations, Internet infrastructure providers, and telecommunications firms in North America, North Africa, and the Middle East.
FireEye, which has been tracking the threat for the last several months, this week described the DNS hijacking campaign as notable for its almost unprecedented scale.
In a report yesterday, the security vendor said that it has so far not been able to attribute the attacks to any particular threat group. However, available evidence — including IP addresses and the machines used to intercept, record, and forward network traffic — suggest the attacker is based in Iran. Some of the organizations that the group has targeted so far, including governments in the Middle East, are also entities that would be of interest to the Iranian government, according to FireEye.
"The implications are tricky," says Ben Read, senior manager for cyber espionage analysis at FireEye. "Malicious actors could have access to sensitive data, they can intercept email, without having anything on your internal network," he says.
Last November, Cisco's Talos group had reported on a campaign it called DNSpionage, which is aimed at organizations in Lebanon and the United Arab Emirates. In a report, Talos described the activity as involving the use of fake job websites to drop malware on systems within target organizations. Attackers were also attempting to redirect DNS traffic belonging to several government and private domains in the country in an apparent information-gathering effort, Talos noted.
The campaign that FireEye reported on appears to be a continuation and expansion of the same one that Talos described last November.
Read says FireEye has so far not been able to determine how exactly the attackers are gaining access to the DNS records. But it is possible they are using multiple techniques to get initial access to them.
The attackers have manipulated DNS records in at least three different ways. In some cases, the attackers have altered the "DNS A" records that are used for mapping domain names to IP addresses, so traffic bound for one domain gets redirected through one controlled by the attackers.
The second method the attackers have used is to alter DNS NS records and point a victim organization's nameserver record to an attacker-controlled domain. In addition, the attackers have also employed a DNS Redirector "operations box" that is designed to respond with an attacker-controlled IP address to DNS requests for victim domains, FireEye said in its report this week.
If the domain name is not part of the targeted zone, the requested IP is returned to the user, FireEye said.
After the attackers alter the DNS records, they have used fraudulent Let's Encrypt certificates to ensure that any traffic that is being rerouted remains encrypted in order not to arouse suspicion, Read notes.
Kris Beevers, CEO of NS1, says the hijacking attacks of the sort that FireEye reported are easy to pull off. Often, all that a bad actor has to do in order to manipulate a DNS record is to take over the login credentials to the DNS provider and registrars.
"They can also use BGP hijacking or [take] over the DNS resolver that a specific target user is using and [by] man-in-the-middling," Beevers says.
Attacks like these highlight the need for organizations to use strong authentication to protect access to the domain's administration panel, Read says.
Organizations should also make it a practice to monitor authorized DNS activity logs for unexpected changes and enable DNSSEC to verify the authenticity of information received from authoritative DNS servers, Beevers says.